This invention relates to the discovery and asexual propagation of a new and distinct variety of Pistachio tree, Pistachio atlantica (unpatented)×P. integerrima (unpatented), cv. ‘Wonderful Pistachio Rootstock #4’ as herein described and illustrated. The new variety was first selected as breeder number ‘SR412-5’. The new variety is a hybrid of P. atlantica and P. integerrima which was first discovered on cultivated land from trees grown from seed produced by a cross of the two parent varieties. The new variety was discovered, further characterized, and propagated by Joe Macllvaine, Eric Mercure and John Etchamendy in the San Joaquin Valley, Kern County, Calif.
The new variety ‘Wonderful Pistachio Rootstock #4’ is characterized by producing large leaves, reddish-green new foliage, dark green mature foliage and upright habits with rounded crown. The new variety is useful as a rootstock to nut bearing pistachio.
The male parent is P. integerrima (unpatented) and the female parent is P. atlantica (unpatented). The date of first planting was 1996, and the date of first flowering was 2000.
The new variety ‘Wonderful Pistachio Rootstock #4’ was first asexually propagated in 2013 by Eric Mercure by tissue culture in the Southern San Joaquin Valley in Kern County, Calif. and established and transmitted through succeeding propagation by air-layering.
The new variety ‘Wonderful Pistachio Rootstock #4’ differs from its male parent P. integerrima in that the leaves and leaflets are shorter. Also, the leaflet base is more rounded in the new variety. In addition, the leaves are less red when emerging and fall off sooner.
The new variety ‘Wonderful Pistachio Rootstock #4’ differs from its female parent P. atlantica in that new variety is more vigorous and is believed to be more resistant to verticillium disease. The leaflets of the new variety are smaller and less rounded with a faster growth rate. The new variety has an overall larger size canopy.
The new variety can be distinguished from other available varieties by its yield characteristics. The closest available varieties are Integerrima “Pioneer Gold” and UCB1, an atlantica×integerrima hybrid. Yields on P. vera have been observed to be consistently higher on mature trees on the new rootstock variety when compared to Pioneer Gold and UCB1. The new variety ‘Wonderful Pistachio Rootstock #4’ has a 65% improved yield over the average yield from P. vera on UCB1. The yield of the new variety ‘Wonderful Pistachio Rootstock #4’ was measured from 2004-2013.
The new variety ‘Wonderful Pistachio Rootstock #4’ can also be distinguished from “Pioneer Gold” by the leaf shape.
The new ‘Wonderful Pistachio Rootstock #4’ has been shown to maintain its distinguishing characteristics through successive asexual propagations by, for example, tissue culture and air layering.
Variations of the usual magnitude from the characteristics described herein may occur with changes in growing conditions, irrigation, fertilization, pruning, management and with climatic variation.